Objective: To explore the clinical value of left atrium volume tracking (LAVT) technique in assessment of left atrium (LA) volume and function changes in patients with constrictive pericarditis (CP). Methods: Twenty CP patients who underwent pericardiectomy were enrolled. LA volume parameters, including LA maximum volume (LAVmax), pre-contraction volume (LAVpre) and minimum volume (LAVmin) were obtained in CP patients before (preoperative group) and after pericardiectomy (postoperative group), also in 20 healthy subjects (control group) with LAVT technique. The measured volume parameters were calibrated with body surface area,and then LAVImax, LAVIpre, LAVImin were obtained. Systolic filling rate of LA (dv/dtS), early diastolic emptying rate of LA (dv/dtE) and late diastolic emptying rate of LA (dv/dtA) were measured according to LA volume change velocity curve obtained with LAVT. Then LA total ejection fraction (LATEF), LA passive ejection fraction (LAPEF) and LA active ejection fraction (LAAEF) were also calculated. The parameters were compared among groups. Results: Obvious differences of LAVImin were found among 3 groups (P<0.05). LAVImin in preoperative group and postoperative group were higher than that in control group (both P<0.05), while in preoperative group was higher than that in postoperative group (P<0.05). There were statistical differences of LATEF, LAPEF, LAAEF, dv/dtS, dv/dtE and dv/dtA among 3 groups (all P<0.05), those in preoperative group and postoperative group were lower than in control group (all P<0.05), in preoperative group were lower than in postoperative group (all P<0.05). Conclusion: LAVT can be used to accurately assess changes of LA volume and function in CP patients before and after pericardiectomy.

Objectives:Microvascular obstruction (MVO) is a specific cardiac magnetic resonance (CMR) imaging feature in patients with acute myocardial infarction. The purpose of this study was to elucidate the predictive value of MVO in left ventricular adverse remodeling after primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI).Methods:A total of 167 patients with STEMI undergoing primary PCI in the Chinese PLA General Hospital from 2016 to 2020 were enrolled in this prospective cohort study, the average age of study patients was 57±10 years old, with 151 males (90.4%) and 16 females (9.6%). The patients were divided into the MVO group ( n=81) and non-MVO group ( n=86) according to the presence or absence of MVO on CMR imaging, respectively. The primary endpoint of the study was the occurrence of left ventricular adverse remodeling, which was defined as an increase in left ventricular end diastolic volume (LVEDV) by >20% at 6 months after primary PCI compared with the baseline. Patients who completed follow-up were diagnosed as left ventricular adverse remodeling or no left ventricular adverse remodeling according to CMR. The baseline data, perioperative data, and related data of end points were compared between the MVO group and non-MVO group. Finally, the predictive value of MVO in left ventricular adverse remodeling was calculated by receiver operating characteristic curve analysis. Results:In the baseline data, preoperative thrombolysis in myocardial infarction (TIMI) flow ( χ2=13.74, P=0.003) and postoperative TIMI flow ( χ2=14.87, P=0.001) were both obviously decreased in the MVO group. After 6 months of follow-up, the incidence of left ventricular adverse remodeling in the MVO group was significantly higher than that in the non-MVO group [37.0%(27/73) vs. 18.9%(14/74), χ2=5.96, P=0.015]. The left ventricular end systolic volume at 6 months post infarction in the MVO group was significantly larger than that in the non-MVO group [(94±32) vs. (68±20) ml, t=-5.98, P<0.001], as well as the LVEDV [(169±38) vs. (143±29) ml, t=-4.74, P<0.001]. Receiver operating characteristic curve showed that the area under the curve of MVO size for predicting left ventricular adverse remodeling was 0.637. Conclusion:The risk of left ventricular adverse remodeling is significantly increased in patients with MVO after primary PCI for acute STEMI.